Adapter assembly having wedge head with saddle fit latch for impact tool units

ABSTRACT

An adapter assembly associated with the lower end of the support housing of an impact tool unit and the tool bit extending from the lower end thereof. The impact tool unit is of the general type in which the impact motor is not connected directly to the outer support housing but is mounted for upward axial movement in the housing, as a result of recoil forces, to substantially reduce shock and vibration transmitted to the operator who holds the unit by means of a handle carried by the housing. The adapter assembly cooperates with the tool bit to hold it down against the work but permits the tool bit to rotate or oscillate about its axis or to remain in a stationary position angularly relative to the axis depending on the type of impact motor being used. The assembly includes a wedge head carried on the lower end of the tool chuck which may follow the tool bit into the work to aid in loosening up the material. The wedge head carries a pivoted latch member which holds the tool bit within the assembly but can be released to permit removal and replacement of the bit. This latch member has a special saddle support associated therewith designed to take the impact forces on the latch member and its pivot pin to prevent damage thereto.

United States Patent [1 1 Price 1 1 ADAPTER ASSEMBLY HAVING WEDGE HEAD WITH SADDLE FIT LATCH FOR IMPACT TOOL UNITS [76] Inventor: Vernon L. Price, 670 Hillcrest Dr.,

Reno, Nev. 89502 [22] Filed: Dec. 8, 1972 [21] Appl. No.: 313,464

[521' US. Cl 173/133, 173/139, 173/162, 279/19.1 [51] Int. Cl. B25d 17/08 [58] Field of Search 279/19, 19.1, 19.2, 19.3, 279/19.4, 19.6, 19.7, 20, 77; 173/139, 162, 133; 299/94 [56] References Cited UNITED STATES PATENTS 1,605,941 1 H1926 Hansen 279/77 UX 1,784,012 12/1930 .lowett 299/94 X 1,792,875 2/1931 Stevens 279/19 X 2,265,427 12/1941 Fuehrer 279/l9.l X 2,489,923 11/1949 Nast 279/l9,l X 3,356,166 12/1967 Diachenko 279/19 X Primary Examiner--Ernest R. Purser Assistant Examiner-William F. Pate, 111 Attorney, Agent, or FirmLimbach, Limbach & Sutton [451 Feb. 11, 1975 1 1 ABSTRACT An adapter assembly associated with the lower end of the support housing of an impact tool unit and the tool bit extending from the lower end thereof. The impact tool unit is of the general type in which the impact motor is not connected directly to the outer support housing but is mounted for upward axial movement in the housing, as a result of recoil forces, to substantially reduce shock and vibration transmitted to the operator who holds the unit by means of a handle carried by the housing. The adapter assembly cooperates with the tool bit to hold it down against the work but permits the tool bit to rotate or oscillate about its axis or to remain in a stationary position angularly relative to the axis depending on the type of impact motor being used. The assembly includes a wedge head carried on the lower end of the tool chuck which may follow the tool bit into the work to aid in loosening up the material. The wedge head carries a pivoted latch member which holds the tool bit within the assembly but can be released to permit removal and replacement of the bit. This latch member has a special saddle support associated therewith designed to take the impact forces on the latch member and its pivot pin to prevent damage thereto.

5 Claims, 7 Drawing Figures PATENTEB FEB] 1 I975 SHEET 10F 3 II lnlklvlclla PATENTEBFEBI 1 I975 3 .865, 1 98 SHEEI 3 OF 3 ADAPTER ASSEMBLY HAVING WEDGE HEAD WITH SADDLE- FIT LATCH FOR IMPACT TOOL UNITS The adapter assembly having wedge head with saddle-fit latch, of may invention, is preferably incorporated in an impact tool unit including an air motor and of the general type disclosed in my US. Pat. No. 3,223,181 issued Dec. 14, 1965. In that patent, I have disclosed an outer muffler or support housing having a handle structure for the operator and an inner air motor which is mounted within the housing for upward movement relative thereto so that recoil from the tool bit is transmitted to the motor but not to the outer housing with its handle structure.

In an impact tool unit of this type, in order for it to do much more efficient work, it is desirable to provide means for holding the working bit down against the work instead of permitting it to bounce freely when the tool bit itself absorbs a certain portion of the impact blow. According to this invention, I have provided an adapter assembly which makes it possible to hold the bit down against the work but which will permit the tool bit to rotate or oscillate about its axis during use with rotary impact motors, or to remain non-rotary as needed with non-rotary motors. This adapter assembly includes an elongated chuck on the motor which extends from the lower end of the outer housing and which carries a wedge-shaped head depending therefrom and through which the tool bit projects. This wedge-shaped head is designed to follow the tool bit into the crack or opening it forms and exert a wedging action on the material to aid in breaking up the material and preventing sticking of the bit therein. As another important feature of this invention, the wedge head carries a pivoted saddle-fit latch member which will normally be held in such a position that it will cooperate with the tool bit shoulder or flange ring to prevent the bit from dropping from the chuck but which can be moved to a releasing position to permit release of the bit. To prevent the latch member or its pivot pin from being damaged as a result of impact forces as the head wedges into the material, the head is provided with a saddle-type bearing for engaging a complemental portion on the latch member to absorb any blows or forces to which the latch member is subjected.

The best mode contemplated in carrying out my invention is illustrated in the accompanying drawings in which:

FIG. I is an axial sectional view of the assembly on the lower end of an impact tool unit of a non-rotating type.

FIG. 2 is a side elevational view of the assembly.

FIG. 3 is an axial sectional view taken at the position indicated at line 3-3 of FIG. I but showing more of the tool unit and the tool bit in a different position.

FIG. 4 is an enlarged transverse sectional view taken along line 4-4 of FIG. 3.

FIG. 5 is an enlarged transverse sectional view taken along line 5-5 of FIG. 3.

FIG. 6 is an exploded view in perspective, partly broken away. showing various parts of the assembly.

FIG. 7 is a transverse sectional view taken along line 77 of FIG. I.

With reference to the drawings, the assembly of my invention is shown on the lower end of a non-rotating impact tool unit which is of the general type disclosed in my said US. Pat. No. 3,223,181. The details of the air impact motor of that patent are not disclosed herein but it is indicated generally by the numeral 8. The lower end or cap of an outer support housing is indicated at 9 and the housing is indicated at 10. The chuck II is supported by and extends downwardly from the impact motor 8. The chuck holds the usual tool bit 12, which is usually of hexagonal cross-section and is provided with the integral annular shoulder or ring 13. As indicated in said patent, the impact motor and the support or muffler housing are mounted for relative axial movement so that recoil forces will not be transmitted to the outer support housing which will be held by the operator through the medium of a handle carried thereby. Therefore, the adapter assembly shown herein provides for upward axial movement of the chuck 11 relative to the support housing 10 and cap 9 in response to recoil forces as the tool bit 12 engages the work. Thus, these forces will not be transmitted to the operator.

The cap 9 of the housing 10 is provided with a bush ing-receiving opening at its lower end for receiving the support bushing 15. This bushing 15 includes a main body insertable from above in the shouldered opening or socket 20 of the cap 9 and having a lower clamp ring 16 threaded thereon to retain it in the opening with its upper flange I7 resting on an associated shoulder or ledge surrounding the opening. Thus, the flanged support bushing assembly will remain in axial position within the lower end of the cap 9, being clamped therein and prevented from moving both axially and angularly. This support bushing 15 is provided with a pair of radially inwardly extending opposed ears 18 having inner ends which are spaced a predetermined distance apart, these ears being formed at the upper ends of radially inwardly extending lugs 19 which extend a substantial portion of the height of the bushing 15. The chuck II is of tubular or sleeve-like form and its lower portion is adapted to extend into and cooperate with the bushing assembly 15.

The chuck 11 is mounted for axial or vertical reciprocal sliding movement in the support bushing 15 but is prevented from rotating or oscillating therein. To accomplish this, the chuck sleeve 11 is provided with diametrically opposed vertically elongated slots 21 for receiving the opposed lugs 19 of the bushing 15. These slots are closed at their upper end but their lower ends are at the lower end of the chuck and are open. However, the lower end of the chuck is threaded at 24 to receive the threaded wedge-shaped head 25. The head will thus close the lower ends of the elongated slots 21. The chuck 11 will be permitted to move vertically relative to the bushing 15 because of the slots 21, but rotation of the chuck in the bushing will be prevented by the radially extending lugs 19 cooperating with the walls of the slots.

Within the chuck I1, I non-rotatably mount a bushing 26 which has a cylindrical outer surface press-fitted into the interior of the chuck. In addition, set screws 26a are threaded through the wall ofthe chuck into engagement with the bushing 26 to prevent rotation thereof. The inner surface of the bushing 26 is hexagonal and complemental to the tool bit surface and slidably receives the tool bit 12. The lower end of this bushing 26 is disposed at a level corresponding to the top closed ends of the chuck slots 21 and it will be noted that the ears 18 on the lugs 19 will extend inwardly below the bushing 26. Thus, downward movement of the chuck 11 relative to the housing will be limited by contact of the lugs 19 with the upper ends of the slots 21 in the chuck. It will be noted that the inner ends of the ears 18 will be adjacent outer angular surfaces of the bit 12.

Below the bushing ears l8 and above the shoulder 13 of the tool bit 12, I provide the bushing 27 on the tool bit. The bushing is provided with an outer cylindrical surface which rotatably engages the inner tubular surface of the chuck 11 and an inner hexagonal surface which slideably but non-rotatably engages the hexagonal surface of the tool bit. Above the bushing 27 is a thrust collar 28 which has an annular outer surface rotatable on the chuck and a hexagonal inner surface slideably engaging the tool bit. This collar 28 will be located between the upper end of the bushing 27 and the ears 18. It will be noted that the inner edges 22 of the lugs 19 are curved complemental to the adjacent outer surface of the lower bushing 27. Thus, the tool bit will be free to move axially relative to the hexagonal lower and upper bushings 27 and 26 but the tool bit will not rotate.

During operation of an impact motor of the nonrotating type, the adapter assembly will be in the condition shown in FIG. 3. The tool bit 12 will be forced upwardly when its lower end engages the work, causing the tool shoulder 13 to push upwardly on the hex bushing 27 which will push the thrust collar 28 upwardly against the ears 18 of the support bushing 15. The slots 21 in the chuck 11 will extend vertically sufficiently that their upper ends will not engage the bushing during the impact operation. Impact reaction forces will be transmitted upwardly through the tool bit 12 to the tappet within the impact motor to move the motor upwardly without transmitting these vibrations to the outer housing or support 10 and through the handle carried by the housing to the operator. During the impact or pounding action on the tool bit, it is held down against the work by engagement of the lower end of the bushing 27 with the bit shoulder 13, even though recoil forces will move the impact motor and chuck 11 vertically upwardly within the outer housing 10 and cap 9 carried thereby. The tool bit 12 is held down against the work by means of the ears [8 of the support bushing 15, carried by the casing 10, through the thrust bearing 28 and hex bushing 27. This holding of the bit 12 down into the work facilitates penetration of the tool bit into the material. The adapter assembly of this invention permits this action, but still does not interfere with the no vibration arrangement for the outer housing as disclosed in my prior patent.

When resistance to downward movement of the tool bit 12 is not present, the bit will drop to the position indicated in FIG. 1 where the tool bit shoulder 13 will engage the latch 30, carried by the head 25, that will prevent it from dropping farther. At this time, the hex bushing 27 and collar 28 may drop downwardly, but the upper ends of the slots 21 in the chuck will engage the bushing 15 when the tool is lifted over to a new position.

According to my present invention, the head 25 and the latch 30 carried thereby are of special construction and arrangement. The head 25 is heavy and rugged and is wedge-shaped in vertical cross-section pointing downwardly as indicated in FIGS. 1 and 2. The head 25 is provided with an upwardly opening socket for receiving the threaded chuck end 24 which will engage with the bottom 31 of the socket. A set screw 32 may be threaded through the wall of the socket into engagement with the chuck end 24 to hold the head 25 in a set position on the chuck, preferably with the latch located at the front side of the tool.

It will be noted that the head 25 has a vertical bore 29 which is sufficiently large to permit passage of the tool ring or shoulder 13. At the one side of the head and intermediate its height, it is provided with an opening 33 (FIG. 7), extending completely through the wall thereof, for receiving the latch member 30. This latch member is generally L-form in vertical cross-section (FIGS. 1 and 2), having the upstanding actuating arm portion 34 and the inwardly extending tool engaging portion 35, the L-shaped member being pivoted at its angle to the head by means of a heavy pivot pin 36 extending transversely through the opening 33. The toolengaging portion is of semi-circular shape and will swing into position for engagement with the flange ring 13 (FIG. 1), on the tool bit 12. At this time, the actuating arm portion 34 will be upwardly. The latch member 30 will be held in this upper position by a springpressed keeper 39 projecting downwardly from surface 38 and engaging surface 37. To release the latch 30, the tool bit 12 will be moved upwardly to raise the flange ring 13 so that the latch portion 35 can be swung upwardly and outwardly to the broken line position where it will then permit the the flange ring 13 to pass downwardly to be removed. To prevent damage to the pivot pin 36 by the tool ring 13 imparting downward impact forces to the engaging portion 35 of the latch, a saddle bearing arrangement is provided which includes the V- saddle on the bottom side of the latch contact portion and a complemental bearing surface on the head 25 at the lower side of the opening 33. Thus, downward forces on the engaging portion 35 will be borne by the saddle bearing 40 rather than the pin 36. This will prevent deforming or breaking of the pin or latch member. With the latch structure, the tool bit can be removed and replaced readily.

The head 25 being of wedge-shape can follow the tool bit into a hole or crack it produces. This will aid in breaking up the material and facilitate removal of the bit.

My invention has been described above as being applied to a tool unit with a non-rotating impact motor. However, although I have not illustrated a rotary impact motor, since the details thereof are well known, it should be understood that my invention is equally applicable thereto. If a rotary impact motor is employed, it would be similarly mounted in the outer housing so that recoil from the tool bit would be transmitted to the motor, but not to the outer housing. The adapter assembly of my invention could be applied to the outer end of the housing 10 in exactly the same manner as described except that the bushing 26 would be mounted in the chuck 12 for free rotation therein. Thus, the tool bit could rotate or oscillate as it was pounded into the work. Also, it would be possible to use the adapter assembly of this invention with an anti-friction rotary bearing of the type disclosed in FIG. 5 of my copending application, Docket No. -Ol2. In either case, the tool bit could rotate or oscillate as it was forced into the work. The adapter assembly in each case would include the wedge-head with saddle-fit latch.

The adapter assembly can be used with the no vibration structure of my prior patent and will hold the tool bit down against the work during the impact operation. The head is of wedge form and will aid in breaking'up the material and in preventing the tool bit from sticking into the material. The latch will be rugged and protected and will effectively engage the tool bit in the chuck when needed and can be actuated readily to release the bit.

Having thus described this invention, what is claimed 1. In combination with an impact tool including an impact motor, a support having a socket which opens outwardly and in which a tool bit is axially inwardly inserted, said bit having a shoulder formed thereon, and including:

means for releasably retaining said bit in said socket an for receiving impacts from said impact motor means;

said means comprising a hollow head mounted on said support and having a socket axially aligned with the socket in said support and through which the bit axially extends; said socket having a side opening that extends outwardly through the wall of the socket at a level above the lower end of the head;

a releasable latch member pivoted in said opening by a pivot pin extending transversely thereof above the lower side of the opening;

said latch member having a tool bit shoulder engaging portion inwardly of the pivot pin and an actuating portion outwardly of the pin;

a saddle bearing portion at the lower side of the opening; and

a complemental bearing surface on the latch member at its lower side for engaging said saddle bearing portion, said saddle bearing portion and said complemental bearing surface cooperating to transmit impact and vibrational forces therebetween whereby the forces on said pivot pin are reduced.

2. The combination of claim 1 in which said shoulder of the tool bit is in the form of a ring flange and;

said shoulder engaging portion of the latch member is of arcuate form for engaging said ring flange.

3. The combination of claim 2 including yieldable keeper means for normally keeping said latch member in its inner shoulder-engaging position.

4. The combination of claim 1 wherein said head is wedge-shaped to aid said tool bit.

5. The combination of claim 4 wherein said impact tool includes an outer housing and wherein said retaining means forms a part of said outer housing. 

1. In combination with an impact tool including an impact motor, a support having a socket which opens outwardly and in which a tool bit is axially inwardly inserted, said bit having a shoulder formed thereon, and including: means for releasably retaining said bit in said socket an for receiving impacts from said impact motor means; said means comprising a hollow head mounted on said support and having a socket axially aligned with the socket in said support and through which the bit axially extends; said socket having a side opening that extends outwardly through the wall of the socket at a level above the lower end of the head; a releasable latch member pivoted in said opening by a pivot pin extending transversely thereof above the lower side of the opening; said latch member having a tool bit shoulder engaging portion inwardly of the pivot pin and an actuating portion outwardly of the pin; a saddle bearing portion at the lower side of the opening; and a complemental bearing surface on the latch member at its lower side for engaging said saddle bearing portion, said saddle bearing portion and said complemental bearing surface cooperating to transmit impact and vibrational forces therebetween whereby the forces on said pivot pin are reduced.
 2. The combination of claim 1 in which said shoulder of the tool bit is in the form of a ring flange and; said shoulder engaging portion of the latch member is of arcuate form for engaging said ring flange.
 3. The combination of claim 2 including yieldable keeper means for normally keeping said latch member in its inner shoulder-engaging position.
 4. The combination of claim 1 wherein said head is wedge-shaped to aid said tool bit.
 5. The combination of claim 4 wherein said impact tool includes an outer housing and wherein said retaining means forms a part of said outer housing. 